Integrated speech processor headpiece

ABSTRACT

An integrated headpiece for a cochlear implant system includes a microphone for outputting an audio signal; signal processing electronics for processing the audio signal; and a transmitter for transmitting a processed audio signal received from the electronics to an implanted receiver. All of the microphone, signal processing electronics, and transmitter are disposed in a common housing of the integrated headpiece. The headpiece may also be one of a set of headpieces that can be alternatively used as needed to suit power consumption requirements or environmental conditions. 
     Cochlear implant systems include a circuit board having electronic circuitry configured to generate one or more signals configured to direct electrical stimulation of one or more stimulation sites within a patient, an induction coil configured to transmit a telemetry signal by generating a telemetry magnetic field, and a telemetry flux guide positioned between the induction coil and the circuit board. The telemetry flux guide is configured to direct magnetic flux of the telemetry magnetic field away from the circuit board.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.12/398,058, filed Mar. 4, 2009, now U.S. Pat. No. 8,811,643, whichclaims priority under 35 U.S.C. §119(e) to U.S. Provisional ApplicationNo. 61/113,675, by Scott A. Crawford et al., filed on Nov. 12, 2008, andentitled “Integrated Cochlear Implant Headpiece,” which application ishereby incorporated by reference in its entirety. U.S. application Ser.No. 12/398,058 is also a continuation-in-part, and claims the benefitunder 35 U.S.C. §120, of U.S. application Ser. No. 10/823,880, filedApr. 14, 2004, now U.S. Pat. No. 7,599,508, which claims the benefitunder 35 U.S.C. §119(e) of U.S. Provisional Application No. 60/469,082,filed May 8, 2003. These applications are hereby incorporated byreference in their entireties.

Additionally, companion case Attorney Docket No. 40328-0173, filed onthe same day as U.S. application Ser. No. 12/398,058 and entitled“Modular Speech Processor” is hereby incorporated by reference in itsentirety.

BACKGROUND

In human hearing, hair cells in the cochlea respond to sound waves andproduce corresponding auditory nerve impulses. These nerve impulses arethen conducted to the brain and perceived as sound.

Hearing loss, which may be due to many different causes, is generally oftwo types: conductive and sensorineural. Conductive hearing losstypically occurs where the normal mechanical pathways for sound to reachthe hair cells in the cochlea are impeded, for example, from damage tothe ossicles. Conductive hearing loss may often be helped by usingconventional hearing aids that amplify sounds so that acousticinformation can reach the cochlea and the hair cells. Some types ofconductive hearing loss are also amenable to alleviation by surgicalprocedures.

Many people who are profoundly deaf, however, have sensorineural hearingloss. This type of hearing loss can arise from the absence or thedestruction of the hair cells in the cochlea which then no longertransduce acoustic signals into auditory nerve impulses. Individualswith sensorineural hearing loss may be unable to derive any meaningfulbenefit from conventional hearing aid systems no matter how loud theacoustic stimulus is. This is because the mechanism for transducingsound energy into auditory nerve impulses has been damaged. Thus, in theabsence of properly functioning hair cells, auditory nerve impulsescannot be generated directly from sounds.

To overcome sensorineural deafness, cochlear implant systems or cochlearprostheses have been developed that can bypass the hair cells located inthe cochlea by presenting electrical stimulation directly to theauditory nerve fibers. This leads to the perception of sound in thebrain and provides at least partial restoration of hearing function.Most of these cochlear prosthesis systems treat sensorineural deficit bystimulating the ganglion cells in the cochlea directly using animplanted electrode or lead that has an electrode array. Thus, acochlear prosthesis operates by directly stimulating the auditory nervecells, bypassing the defective cochlear hair cells that normallytransduce acoustic energy into electrical activity to the connectedauditory nerve cells.

Prior to stimulating the nerve cells, the electronic circuitry and theelectrode array of the cochlear prosthesis separate acoustic signalsinto a number of parallel channels of information, each representing anarrow band of frequencies within the perceived audio spectrum. Ideally,each channel of information should be conveyed selectively to a subsetof auditory nerve cells that normally transmit information about thatfrequency band to the brain. Those nerve cells are arranged in anorderly tonotopic sequence, from the highest frequencies at the basalend of the cochlear spiral to progressively lower frequencies towardsthe apex.

A cochlear implant system typically comprises both an external unit thatreceives and processes ambient sound waves and a cochlear implant thatreceives data from the external unit and uses that data to directlystimulate the auditory nerve. A common configuration for a cochlearimplant system thus involves internal components that are surgicallyimplanted into the patient and external components that provide powerand electrical signals representing environmental sound to the internalcomponents. These external components typically include a Behind-the-Ear(BTE) processor worn on the ear or a body worn processor. Theseprocessors contain a microphone, batteries, and signal circuitry thatprocesses the electrical signals generated by the microphone. Theprocessors are connected to a headpiece by a cable. The headpiecereceives the electrical signals through the cable and transmits them tothe internal components.

In some cochlear implant systems, the cable or cables connecting theexternal components together can present some issues. For example, thecable may have to be routed through clothing or accommodated during hairstyling. The cable may be snagged, pulled on, or tangled, causing theheadpiece to fall off. Additionally, cables are considered unattractiveby many patients and are susceptible to failure due to bending.

An inductive link is commonly used to transmit telemetry signals fromthe external unit to the implanted cochlear stimulator. To this end, theexternal unit often includes an inductive coil that produces a telemetrysignal by generating an electro-magnetic field that is picked up by areceiver on the implanted cochlear stimulator. The inductive coil may behoused in an external headpiece that is positioned on a patient's headto transmit the telemetry signal through the patient's scalp to theimplanted receiver. The external unit often includes a retention magnetfor securing the headpiece to the patient's head so that the inductioncoil is properly positioned adjacent to the implanted receiver.

In a conventional cochlear implant system, electronic circuitry includedwithin the external unit is not placed in relative close proximity tothe induction coil and the retention magnet due to losses andinterference caused by magnetic flux associated with the induction coiland the retention magnet. Hence, the electronic circuitry is typicallyhoused within a behind-the-ear unit, for example, while the inductioncoil and the retention magnet are housed separately within a headpiece.Such a configuration is undesirable for many cochlear implant patients.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate various embodiments of theprinciples described herein and are a part of the specification. Theillustrated embodiments are merely examples and do not limit the scopeof the claims.

FIG. 1 is an illustrative diagram showing a cochlear implant system inuse.

FIG. 2 is a diagram showing external components of an illustrativecochlear implant system.

FIG. 3 is a diagram showing the internal components of an illustrativecochlear implant system.

FIG. 4 is a diagram of various illustrative components which may make upan integrated headpiece, according to one embodiment of principlesdescribed herein.

FIG. 5 is a perspective view of an illustrative integrated headpiece,according to one embodiment of principles described herein.

FIG. 6 is a perspective view of an illustrative integrated headpiece,according to one embodiment of principles described herein.

FIG. 7 is a perspective view of an illustrative integrated headpiece,according to one embodiment of principles described herein.

FIG. 8 is a top view of an illustrative integrated headpiece, accordingto one embodiment of principles described herein.

FIG. 9 is a perspective view of an illustrative integrated headpiece,according to one embodiment of principles described herein.

FIG. 10 is a diagram showing an illustrative integrated headpiece beingworn by a user, according to one embodiment of principles describedherein.

FIG. 11A illustrates an exemplary cochlear implant system according toprinciples described herein.

FIG. 11B illustrates a portion of an exemplary cochlear implant systemaccording to principles described herein.

FIG. 12 is a functional block diagram of an exemplary sound processorand implantable cochlear stimulator according to principles describedherein.

FIG. 13 illustrates a schematic structure of the human cochleahighlighting elements according to principles described herein.

FIG. 14 illustrates an exemplary configuration of a cochlear implantsystem according to principles described herein.

FIG. 15A is an exploded perspective view of an exemplary externalheadpiece according to principles described herein.

FIG. 15B is a perspective view of a portion of an exemplary externalheadpiece according to principles described herein.

FIG. 15C is a cross-sectional side view of a portion of an exemplaryexternal headpiece according to principles described herein.

FIG. 16 illustrates magnetic flux surrounding an induction coil and aretention magnet in an exemplary external headpiece according toprinciples described herein.

Throughout the drawings, identical reference numbers designate similar,but not necessarily identical, elements.

DETAILED DESCRIPTION

As mentioned above, individuals with hearing loss can potentially behelped by a number of different hearing assistance devices. Theseassistive devices are typically worn regularly and over a significantperiod of each day. Consequently, any such hearing assistance deviceshould be robust and reliable. Additionally, the hearing assistancedevice should be visually unobtrusive and not unduly restrict the user'sactivities. As explained above, cochlear implant users typically mustwear at least two separate external units, a processor and a headpiece,that are connected by a cable.

The processor may be a Behind-The-Ear (BTE) processor or a body wornprocessor. A BTE processor typically uses a hook which attaches over thetop of the outer ear and holds the BTE processor in place behind the earof the user. The BTE processor contains a microphone, battery, andelectronics. A cable attaches the BTE processor to the headpiece andconveys data signals and power to the headpiece. The headpiece istypically held in place by magnetic forces generated by a surgicallyimplanted magnet that is a part of the internal cochlear implant.

A body worn processor is typically worn by attaching the processor to anarticle of clothing worn by the user. For example, a body worn processormay be tucked into a pocket or attached to a lapel. The body wornprocessor does not have the severe size and weight constraints that areassociated with a BTE processor. Consequently, the electronics andbattery capacity of the body worn processor can be significantly greaterthan BTE processors. Like the BTE processor, a cable attaches the bodyworn processor to the headpiece.

As mentioned above, the cable or cables connecting the externalcomponents together can be difficult to manage. For example, when achild wears a cochlear implant, the parent may have to take additionalcare in dressing the child and restrict some activities the child wouldotherwise enjoy in order to reduce the chances of the cable beingsnagged, pulled on, tangled, or broken. Additionally, the processor andcable can be visually distracting and are considered unattractive bymany patients. For some patients, the BTE unit can be uncomfortable,particularly those who are sensitive to heavy objects hanging from theirears.

Accordingly, the present specification addresses these issues bydescribing an integrated cochlear implant headpiece that combines theexternal components of the cochlear system into a single unit that isworn directly over the surgically implanted receiver. The integratedcochlear implant headpiece is a head mounted, external component unitwhich provides a stand-alone support for the functionalities of theimplanted components. This eliminates the need for a separate body wornprocessor or BTE processor and the connecting cable. Consequently, theintegrated cochlear implant headpiece reduces the difficulties commonlyassociated with wearing and using a cochlear implant. Specifically,because there is no separate processor unit or connecting cable, thereis no need to route a cable through clothing or hair and no possibilityof snagging or damaging the cable. Additionally, the integrated cochlearimplant headpiece can be significantly less visually intrusive and moreuser friendly. The modular nature of the integrated cochlear implantheadpiece may allow for other devices to communicate with and/or beattached to the integrated cochlear implant headpiece to provideadditional functionality. However, the integrated headpiece isconfigured to provide the basic functionality for the operation of thecochlear implant as a stand alone unit.

In some embodiments, the integrated cochlear implant headpiece may haveone or more accessories which attach to the integrated headpiece andprovide additional functionality. As discussed in U.S. application Ser.No. 10/823,880 (now U.S. Pat. No. 7,599,508), of which the currentapplication is a continuation-in-part, an assistive listening cap maymagnetically attach to the top of the integrated cochlear implant. Theassistive listening device may provide a variety of benefits to thepatient. By way of example and not limitation, the assistive listeningdevice may provide additional battery power; alternative antennas andcircuitry for receiving audio signals via electromagnetic transmission;additional memory capacity; and/or additional signal processingcapability.

Some exemplary cochlear implant systems include a circuit board havingelectronic circuitry configured to generate one or more signalsconfigured to direct electrical stimulation of one or more stimulationsites within a patient, an induction coil configured to transmit atelemetry signal by generating a telemetry magnetic field, and atelemetry flux guide positioned between the induction coil and thecircuit board. The telemetry flux guide is configured to direct magneticflux of the telemetry magnetic field away from the circuit board.

Some exemplary cochlear implant systems include a circuit board havingelectronic circuitry configured to generate one or more signalsconfigured to direct electrical stimulation of one or more stimulationsites within a patient, a retention magnet configured to produce aretention magnetic field for securing one or more components of thecochlear implant system to a head of said patient, and a retention fluxguide positioned between the retention magnet and the circuit board. Theretention flux guide is configured to direct magnetic flux of theretention magnetic field away from the circuit board.

Some exemplary external headpieces for use in cochlear implant systemsinclude a circuit board having electronic circuitry configured togenerate one or more signals configured to direct electrical stimulationof one or more stimulation sites within a patient. The externalheadpieces further include an induction coil configured to transmit atelemetry signal by generating a telemetry magnetic field and atelemetry flux guide positioned between the induction coil and thecircuit board. The telemetry flux guide is configured to direct magneticflux of the telemetry magnetic field away from the circuit board.

In the following description, for purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of the present systems and methods. It will be apparent,however, to one skilled in the art that the present systems and methodsmay be practiced without these specific details. Reference in thespecification to “an embodiment,” “an example,” or similar languagemeans that a particular feature, structure, or characteristic describedin connection with the embodiment or example is included in at leastthat one embodiment, but not necessarily in other embodiments. Thevarious instances of the phrase “in one embodiment” or similar phrasesin various places in the specification are not necessarily all referringto the same embodiment.

Throughout the specification, a cochlear implant system which includes aBehind-The-Ear (BTE) processor and headpiece is used as an example of atypical cochlear implant system. As used in the specification andappended claims the term “headpiece” refers to an external componentthat is located on the head in proximity to an internal receiver, asopposed to a BTE processor or body worn processor.

FIG. 1 is a diagram showing one illustrative embodiment of a cochlearimplant 100 which is surgically placed within the patient's auditorysystem. Ordinarily, sound enters the outer ear 110 and is directed intothe auditory canal 120 where the sound wave vibrates the tympanicmembrane 130. The motion of the tympanic membrane is amplified andtransmitted through the ossicular chain 140 which consists of threebones in the middle ear. The third bone of the ossicular chain, thestirrup 145, contacts the outer surface of the cochlea 150 and causesmovement of the fluid within the cochlea 150. Cochlear hair cellsrespond to the fluid-borne vibration in the cochlea 150 and triggerneural electrical signals that are conducted from the cochlea 150 to theauditory cortex by the auditory nerve 160.

As indicated above, the cochlear implant 100 is a surgically implantedelectronic device that provides a sense of sound to a person who isprofoundly deaf or severely hard of hearing. In many cases, deafness iscaused by the absence or destruction of the hair cells in the cochlea,i.e., sensorineural hearing loss. In the absence of properly functioninghair cells, there is no way auditory nerve impulses can be directlygenerated from ambient sound. Thus, conventional hearing aids, whichamplify external sound waves, provide little benefit to personssuffering from significant sensorineural hearing loss.

Unlike hearing aids, the cochlear implant 100 does not amplify sound,but works by directly stimulating any functioning auditory nerve cellsinside the cochlea 150 with electrical impulses. Cochlear prosthesistypically involves the implantation of electrodes into the cochlea. Thecochlear implant operates by direct electrical stimulation of theauditory nerve cells, bypassing the defective cochlear hair cells thatnormally traduce acoustic energy into electrical energy.

External components of the cochlear implant system include a BTE unit175 which contains the speech processor and has a microphone 170, acable 177, and a transmitter 180. The microphone 170 picks up sound fromthe environment and converts it into electrical impulses. The speechprocessor within the BTE unit 175 selectively filters and manipulatesthe electrical impulses and sends the processed electrical signalsthrough a cable 177 to the transmitter 180. The transmitter 180 receivesthe processed electrical signals from the processor and transmits themto the antenna 187 by electromagnetic induction and/or radiofrequencies. In some cochlear implant systems, the transmitter 180 isheld in place by magnetic attraction with the underlying antenna 187.

The internal components of the cochlear implant include an antenna 187,an internal processor 185, cochlear lead 190, and electrodes 195. Theantenna 187 and internal processor 185 are secured beneath the user'sskin, typically above and behind the external ear 110. As discussedabove, the antenna 187 receives electromagnetic signals and power fromthe transmitter 180. These signals and power are transmitted using awired connection to the internal processor 185. The internal processor185 operates on the received signals and generates modified signalswhich are sent through the cochlear lead 190 to the electrodes 195. Theelectrodes 195 are wound through the cochlea 150 and provide directelectrical stimulation to the auditory nerve inside the cochlea 150.

The cochlear implant stimulates different portions of the cochlea 150according to the frequencies detected by the microphone 170, just as anormal functioning ear would experience stimulation at differentportions of the cochlea depending on the frequency of sound vibratingthe liquid within the cochlea 150. This allows the brain to interpretthe frequency of the sound as if the hair cells of the basilar membranewere functioning properly.

FIG. 2 is an illustrative diagram showing a more detailed view of theexternal components 200 of one embodiment of a cochlear implant system.External components 200 of the cochlear implant system include a BTEunit 175 which comprises a microphone 170, an ear hook 210, a speechprocessor 220, and a battery 230, which may be rechargeable. Themicrophone 170 picks up sound from the environment and converts it intoelectrical impulses. The speech processor 220 selectively filters andmanipulates the electrical impulses and sends the processed electricalsignals through a cable 177 to the transmitter 180. A number of controls240, 245 adjust the operation of the processor 220. These controls mayinclude a volume switch 240 and program selection switch 245. Thetransmitter 180 receives the processed electrical signals from theprocessor 220 and transmits these electrical signals and power from thebattery 230 to the internal components of the cochlear implant byelectromagnetic induction, radio frequencies, optical communication, orany other wireless communication technology.

FIG. 3 is an illustrative diagram showing the internal components 300 ofone embodiment of a cochlear implant. These internal components 300include an antenna 187, an internal processor 185, a cochlear lead 190,and electrodes 195. The internal components 300 of the cochlear implantare surgically implanted such that the electrodes 195 are internal tothe cochlea, as shown in FIG. 1. The antenna 187 and the internalprocessor 185 are secured beneath the user's skin, typically above andbehind the external ear, with the cochlear lead 190 connecting theinternal processor 185 to the electrodes 195. As discussed above, theantenna 187 receives signals from the transmitter 180. These signals arethen passed to the internal processor 185 which may perform variousoperations in the signals to produce modified signals which areparticularly configured to be sent through the cochlear lead 190 to theelectrodes 195. The electrodes 195 are wound through the cochlea andprovide direct electrical stimulation to the auditory nerves inside thecochlea. This provides the user with sensory input that is arepresentation of external sound waves which were sensed by themicrophone 170.

FIG. 4 is an exploded view of components which may be included in anintegrated headpiece 400. The integrated headpiece 400 may include atransmitter antenna 405, a magnet 410, a battery 415, electronics foraudio signal processing 420, and a microphone 430. Headpiece 400 mayalso optionally include a receiver 425 for receiving signals from anexternal source.

As discussed above, the transmitter antenna 405 transmits signals to theimplanted antenna 187 (FIG. 3). According to one embodiment, thetransmitter antenna 405 also inductively transmits power to the internalcomponents. The magnet 410 in the center of the transmitter antenna 405is attracted to an implanted magnetic component that is in the center ofthe implanted antenna 187 (FIG. 3). The attraction between the magnet410 and the implanted magnetic component holds the integrated headpiece400 over the antenna 187 (FIG. 3). The transmitter antenna 405 may alsobe used to receive power to charge the battery 415 when the integratedheadpiece 400 is not in use. For example, the transmitter antenna 405could be used to inductively charge the battery by placing in thetransmitter antenna in proximity to a charging coil through which analternating current is passed. The transmitter coil acts as atransformer coil and receives a portion of the energy. This energy canthen be used to charge the battery within the integrated headpiece. Oneadvantage of using inductive coupling to charge batteries is that theheadpiece can be more easily sealed because there is no need for exposedconductors or connectors.

The magnet 410 may be made from any of a number of magnetic materialsincluding, but not limited to, neodymium-iron-boron, samarium-cobalt,ticonal, alnico, ceramic, magnetic powder in a resin matrix, or othersuitable material. According to one embodiment, materials which exhibita higher magnetic strength per unit volume may be used to minimize thesize of the magnet and integrated headpiece 400.

The battery 415 supplies electrical energy that is required for thefunction of the cochlear implant. Important considerations for a batteryincluded in the integrated headpiece may include the energy density,total capacity of the battery, voltage, robustness, the ability to holda charge over a long period of time, and the ability to be repeatedlycharged and discharged.

By way of example and not limitation, the battery may a lithium ionbattery, a polymer lithium battery, a zinc air battery or other suitablebattery. Polymer lithium batteries operate using the same chemistry asconventional lithium ion batteries but contain the lithium-saltelectrolyte within a solid polymer composite rather than a rigid metalcase. Consequently, polymer lithium batteries can be lighter, moreenergy dense, and less vulnerable to physical damage. Further, polymerlithium batteries can be specifically shaped to fit the device it willpower. Zinc air batteries operate by the oxidation of zinc withatmospheric oxygen. Zinc air batteries have high energy densities andare relatively inexpensive to produce. However, to operate, zinc airbatteries must have direct exposure to the atmosphere, which createschallenges in using these batteries in sealed systems.

The electronics 420 may include components and functionality such aspower conditioning electronics, signal processors, filters, amplifiers,receivers, switches, memory, and other electronics. The principalfunction of the electronics 420 is to receive an audio signal from themicrophone 430 and process that signal into a signal that can betransmitted to the implanted unit to drive stimulation of the cochlea.

A number of additional components may be included in the integratedheadpiece. For example, various visual indicators, such as one or morelight emitting diodes, could also be included. These visual indicatorscould be configured to communicate information regarding the function ofboth internal and external components of the cochlear implant system,such as battery status, the selected program, sensitivity or volumeinformation, and communication status between the headpiece andimplanted receiver.

The integrated headpiece may optionally include a receiver 425. Thereceiver 425 may be any one of a variety of radio frequency (RF), WiFi,IEEE 802.11, Bluetooth®, or other receivers. These receivers candirectly link the cochlear implant system to sound sources, reducingundesirable interference by other noise sources. The sound sources mayinclude a wireless microphone, a remote control device, a cell phone, acomputer, a music player, a personal digital assistant, or other device.For example, in an educational setting, teacher may wear a wirelessmicrophone which transmits the teacher's voice over a radio frequencydirectly to a receiver contained within the integrated headpiece.Similarly, a Bluetooth® receiver could be connected to a stereo, cellphone, or other audio source.

A microphone 430 is also included within the integrated headpiece. Themicrophone 430 may reside directly on the electronics component or maybe a separate component that sends electrical signals through a wiredconnection to the electronics. A variety of microphone types andconfigurations may be used. By way of example and not limitation, themicrophone may use electromagnetic, capacitance change,MicroElectroMechanical Systems (MEMS) or piezoelectric mechanisms toproduce an electrical signal from mechanical vibrations induced bysound. The microphone may also have one of many directional sensitivityprofiles. For example, the microphone may have an omnidirectional,hemispherical, subcardioid, cardioid, or highly directional sensitivityprofile.

FIG. 5 is a diagram showing the components of the illustrativeintegrated headpiece 400 in an assembled configuration. As mentionedabove, the integrated headpiece 400 consolidates all of the externalcomponents of the cochlear implant system in one compact unit. Thiseliminates cables connecting the traditional components together and theassociated problems of routing the cables through clothing or the cablebeing snagged, pulled on, or tangled, causing the headpiece to fall off.Additionally, the integrated headpiece 400 may be more discrete thansystems with multiple components. For example, the integrated headpiece400 may be completely covered by the user's hair or hat. Further, theintegrated headpiece 400 may be more robust than multiple componentconfigurations. The integrated headpiece 400 may be much easier to sealbecause there is no need for external connection or cables.

The components illustrated in FIGS. 4 and 5 can be configured in anumber of different shapes and contained with a variety of housings.FIG. 6 shows one illustrative configuration of an integrated headpiece600. In this illustrative embodiment, a body portion 620 contains thebattery, electronics, microphone, and magnet.

A portion of the transmitter antenna 610 extends beyond the body portion620, forming an open loop. This transmitter antenna configuration mayhave a number of advantages that extend beyond the visual appearance ofthe headpiece 600. For example, the transmitter antenna 610 mayadditionally serve as an inductive pick up which receives electricalenergy from an exterior coil to charge the internal battery.

The exposed portion of the transmitter antenna 610 may also allow formore efficient transfer of the electrical power from the exterior coilbecause the exterior coil could substantially surround the transmitterantenna. In one charging configuration, the exposed portion of thetransmitter antenna 610 may be inserted into a corresponding slot in acharging platform. One or more charging coils could be placed on eitherside of the slot. The transmitter antenna 610 would then be in veryclose proximity to the charging coils. Additionally, the exposed portiontransmitter antenna 610 could assist in the proper positioning andretention of the integrated headpiece 600 within the charging platform.

The integrated headpiece may also have a number of other features. Asmentioned above, visual indicators could be incorporated into theexternal shell of the integrated headpiece to allow a caretaker tovisually ascertain the state and functionality of the integratedheadpiece. By way of example and not limitation, the indicating featuresmay include light emitting diodes which indicate the battery condition.For example, as the battery discharges, a light emitting diode isilluminated to indicate the need to recharge or replace the battery.This could be advantageous for a parent or teacher who can visuallydetermine the battery level.

Similarly, the integrated headpiece may have one or more visual elementswhich indicate the state of the cochlear implant. For example, a lightemitting diode could have a first color and illumination pattern whichindicates that cochlear implant is operational. The light emitting diodecould have a different color and/or illumination pattern for variousmalfunctions such as a malfunction of the integrated headpiece, lack ofcommunication between the integrated headpiece and implanted receiver,or a receiver malfunction.

In the illustrative embodiment shown in FIG. 6, a switch 630 is includedto allow the user to adjust the amplification of the device or to switchbetween a number of predetermined programs. For example, a first programmay be specially adapted for personal conversations with minimalbackground noise, while a second program may be optimized forenvironments with much higher levels of background noise, such as arestaurant or crowded convention venue. A third program setting mayactivate a Radio Frequency (RF) receiver that is linked to a microphoneworn by a teacher, lecturer, or conversationalist. By including externalswitches, the user can adjust the integrated headpiece in real time tosuit a particular sound environment.

FIG. 7 is a perspective view of an illustrative integrated headpiece700. In this illustrative embodiment, the exterior profile of theheadpiece 700 is simplified, which may result in a more robust andinexpensive device. This common rigid housing contains the microphone,signal processing electronics, transmitter and power supply. The rigidhousing maintains its shape during normal handling and providesprotection for the internal components against external contaminants andimpact. Additionally, external switches and visual indicators may beomitted from the headpiece. By eliminating these external features, theheadpiece may be more easily constructed to be waterproof, allowing theuser to walk in the rain, swim, or participate in water sports withoutremoving the headpiece. This will allow the user to continue to receiveauditory signals, thereby enhancing the user's enjoyment of theactivity, ability to interact with others, and increasing the user'ssafety.

According to one embodiment, the headpiece may be linked via a receiverin the headpiece to an external control unit. For example, a number ofcontrols could be incorporated into a key fob. By pressing buttons onthe key fob, wireless signals could be sent to adjust the operationalparameters of the integrated headpiece.

FIG. 8 is a top view of an illustrative integrated headpiece 800 with analternative geometry. In this illustrative embodiment, the transmitterantenna may be contained within a center portion 805 of the integratedheadpiece 800. Other components may be contained within the body portion810. According to one illustrative embodiment, the integrated headpiece800 may additionally include a directional microphone 815. Typically,omnidirectional or hemispherical microphones are used in cochleardevices to better replicate the sensitivity of the human ear. However,in some circumstance it may be beneficial to more selectively senseexternal sounds, thereby reducing background noise. The directionalmicrophone 815 can be used by the patient to selectively amplifyselected sound sources. According to one embodiment, the directionalmicrophone 815 may be pointing in the same direction the patient islooking. For example, a patient may simply turn his head toward one whois speaking to point the directional microphone 815 in the speaker'sdirection to preferentially sense his voice.

The lower cost and ease of wearing the integrated headpiece can lead toa number of benefits. For example, the patient may have two or moreintegrated headpieces. While one integrated headpiece is being worn bythe user, the other integrated headpiece can be recharging its battery.

Additionally or alternatively, the functionality provided by a secondintegrated headpiece may be different. The user can then select theintegrated headpiece that is most appropriate for the situation. Forexample, during a social event, the user may select an integratedheadpiece that is less obtrusive or complements other clothingaccessories. During the course of a normal day, the user may select anintegrated headpiece with a longer lifetime or with a needed receiver.For example, if the user attends school, the user may need a batterythat can supply power throughout the school day and a receiver that canreceive amplified/filtered signals from a wireless microphone worn bythe teacher. If the user is participating in water activities, a sealedheadpiece could be selected.

FIG. 9 is a perspective view of an illustrative integrated headpiece 900with an alternative geometry. According to one embodiment, theintegrated headpiece 900 has a number of lobes 910 which surround acentral body portion 905. These lobes 910 may serve a number purposesincluding increasing the stability of the headpiece, creating a visuallyinteresting profile, increasing the internal volume of the integratedheadpiece 900, providing a shape that is adapted to a particulartransmitter or receiver, or covering a lithium polymer battery which isparticularly shaped to be received by the lobes 910.

FIG. 10 shows an illustrative integrated headpiece 600 being worn by auser 1000. As discussed above, an integrated headpiece is worn over theantenna implantation site. The antenna is typically implanted above andbehind the external ear as shown in FIG. 10. However, the antenna may beimplanted in a variety of other locations.

If desired, the user 1000 can conceal the integrated headpiece 600 byaltering her hair style or wearing a head covering such as a hat, hood,or scarf. If the user has access to a variety of integrated headpieces,the user 1000 can select the integrated headpiece that is most suitedfor a given activity or day. The user may carry one or more backupheadpieces in a pocket, purse, or backpack. If circumstances during theday make it desirable to replace the current integrated headpiece withan alternative headpiece, the user 1000 can simply reach up, grasp theintegrated headpiece 600 and remove it. A second integrated headpiece isthen retrieved, oriented with the magnet side toward the head, andbrought to the approximate location of the implanted antenna. As thesecond integrated headpiece nears the antenna location, the magneticattraction between the two magnetic components moves the integratedheadpiece into the correct location and holds the integrated headpiecein place.

In sum, an integrated headpiece combines the external components of thecochlear implant system into a single unit that is worn directly overthe surgically implanted receiver. This eliminates the need for aseparate body worn processor or BTE processor and the connecting cable.Consequently, the integrated headpiece reduces the complexity of wearingand using a cochlear implant. The integrated headpiece eliminates theneed to route a cable through clothing or hair and the possibility ofsnagging a cable. Additionally, the integrated headpiece can be morerobust, modular, and significantly less visually intrusive thanprocessors of conventional cochlear implant systems.

The telemetry flux guide and techniques for using the same to directmagnetic flux away from the circuitry in a cochlear implant that aredescribed below with reference to FIGS. 11A-16 may be used in thedevices and methods described above with reference to FIGS. 1-10 tocontrol magnetic flux within a cochlear implant device or system.

Cochlear implant systems including an external headpiece that houses acircuit board having electronic circuitry configured to generate one ormore signals configured to control an operation of an implantablecochlear stimulator are described herein. The external headpiece furtherincludes an induction coil configured to transmit a telemetry signal tothe implantable cochlear stimulator by generating a telemetry magneticfield. The external headpiece may additionally include a telemetry fluxguide positioned between the induction coil and the circuit board. Thetelemetry flux guide may be configured to direct magnetic flux of thetelemetry magnetic field away from the circuit board.

In some examples, the external headpiece further includes a retentionmagnet configured to produce a retention magnetic field for securing theheadpiece to a head of the patient. In this case, the external headpiecemay also include a retention flux guide positioned between the retentionmagnet and the circuit board. The retention flux guide may be configuredto direct magnetic flux of the retention magnetic field away from thecircuit board.

FIG. 11A illustrates an exemplary cochlear implant system 1100.Exemplary cochlear implant systems suitable for use as described hereininclude, but are not limited to, those disclosed in U.S. Pat. Nos.6,219,580; 6,272,382; and 6,308,101, all of which are incorporatedherein by reference in their respective entireties. The cochlear implantsystem 1100 of FIG. 11A includes a sound processor portion 1102 and acochlear stimulation portion 1104. The sound processor portion 1102 mayinclude a sound processor 1106, a microphone 1108, and/or additionalcircuitry as best serves a particular application. The cochlearstimulation portion 1104 may include an implantable cochlear stimulator1110, a number of electrodes 1112 disposed on an electrode lead 1114,and/or additional circuitry as best serves a particular application. Thecomponents within the sound processor portion 1102 and the cochlearstimulation portion 1104 will be described in more detail below.

The microphone 1108 of FIG. 11A is configured to sense audio signals andconvert the sensed signals to corresponding electrical signals. In someexamples, the audio signal may include speech. The audio signal mayadditionally or alternatively include music, noise, and/or other sounds.The electrical signals are sent from the microphone 1108 to the soundprocessor 1106 via a communication link 1116. Alternatively, themicrophone 1108 may be connected directly to, or integrated with, thesound processor 1106. The sound processor 1106 processes these convertedaudio signals in accordance with a selected sound processing strategy togenerate appropriate stimulation parameters for controlling theimplantable cochlear stimulator 1110. These stimulation parameters mayspecify or define the polarity, magnitude, location (i.e., whichelectrode pair or electrode group receive the electrical stimulation),stimulation rate, timing (i.e., when the electrical stimulation is to beapplied to a particular electrode pair), spectral tilt, and/or any othercharacteristic of the electrical stimulation that is generated by theimplantable cochlear stimulator 1110.

The electrode lead 1114 shown in FIG. 11A is configured to be insertedwithin a duct of a cochlea. As shown in FIG. 11A, the electrode lead1114 includes a multiplicity of electrodes 1112, e.g., sixteenelectrodes, spaced along its length. It will be understood, however,that any number of electrodes 1112 may be disposed on the electrode lead1114. The electrode lead 1114 may be substantially as shown anddescribed in U.S. Pat. No. 4,819,647 or 6,218,753, each of which isincorporated herein by reference in its respective entirety. As will bedescribed in more detail below, electronic circuitry within theimplantable cochlear stimulator 1110 is configured to generate and applyelectrical stimulation to one or more stimulation sites within thecochlea via selected stimulation channels (i.e., pairs or groups of theindividual electrodes 1112) in accordance with a specified stimulationstrategy defined by the sound processor 1106.

In some examples, the sound processor 1106 and the microphone 1108comprise an external portion of the cochlear implant system 1100, andthe implantable cochlear stimulator 1110 and the electrode lead 1114comprise an implantable portion of the system 1100 that is implantedwithin a patient's body. In alternative embodiments, one or moreportions of the sound processor 1106 are included within the implantableportion of the cochlear implant system 1100.

The implantable cochlear stimulator 1110 and the sound processor 1106may be communicatively coupled via a suitable data or communication link1118, such as a telemetry communication link, as will be described inmore detail below. It will be understood that the data communicationlink 1118 may include a bi-directional communication link and/or one ormore dedicated uni-directional communication links. In some examples,the external and implantable portions of the cochlear implant system1100 may each include one or more inductive coils configured to transmitand receive power and/or control signals via the communication link1118. The control signals may include, for example, the magnitude andpolarity of electrical stimulation representing a sensed audio signal.The external coil may also transmit power from the external portion tothe implantable portion of the cochlear implant system 1100. Powertransmitted to the implantable portion may be used to operate theimplantable portion.

FIG. 11B illustrates a portion of an exemplary cochlear implant systemshowing a communication link 1118 comprising a telemetry communicationlink that may be used in accordance with the present systems andmethods. As illustrated in FIG. 11B, an external portion of the cochlearimplant system 1100 may include an external induction coil 1120 and animplantable portion of the cochlear implant system 1100 may include animplantable induction coil 1122. The external induction coil 1120 may becommunicatively coupled to the sound processor 1106 and the implantableinduction coil 1122 may be communicatively coupled to the implantablecochlear stimulator 1110.

The external induction coil 1120 and the implantable induction coil 1122may include any suitable type of coil capable of generating and/orreceiving an electromagnetic field. For example, the external inductioncoil 1120 and the implantable induction coil 1122 may each include ametallic wire or tube wound in a coiled or otherwise loopedconfiguration. An alternating current may be directed from the soundprocessor 1106 through the external induction coil 1120, therebygenerating a magnetic field surrounding the external induction coil1120. The external induction coil 1120 may be positioned near theimplantable induction coil 1122 such that the implantable induction coil1122 is positioned at least partially within the magnetic fieldgenerated by the external induction coil 1120. The magnetic fieldgenerated by the external induction coil 1120 may cause an electriccurrent to be generated in the internal induction coil 1120. Theelectric current generated in the internal induction coil 1120 may bedirected from the internal induction coil 1120 to the implantablecochlear stimulator 1110. Accordingly, an electric current generated bythe sound processor 1106 may be transferred to the implantable cochlearstimulator 1110 through the communication link 1118 comprising theexternal induction coil 1120 and the implantable induction coil 1122.

The communication link 1118 may function as a telemetry link between thesound processor 1106 and the implantable cochlear stimulator 1110. Forexample, the external induction coil 1120 may transmit one or moretelemetry signals to the implantable induction coil 1122 by generating atelemetry magnetic field as electric current is passed through theexternal induction coil 1120. The telemetry magnetic field generated bythe external induction coil 1120 may produce an electric current in theimplantable induction coil 1122, as described above. The currentgenerated in the implantable induction coil 1122 by the telemetrymagnetic field generated by the external induction coil 1120 may be usedto transfer signals representative of data and/or other information tothe implantable cochlear stimulator 1110 and/or may be used to transferpower to the implantable cochlear stimulator 1110.

In some examples, the communication link 1118 may be used to transmittelemetry signals from the implantable cochlear stimulator 1110 to thesound processor 1106. For example, data acquired by the electrodes 1112and/or status indicators generated by the cochlear stimulator 1112 maybe transmitted to sound processor 1106 via the communication link 1118.To this end, implantable induction coil 1122 may transmit telemetrysignals to the external induction coil 1120 by generating a telemetrymagnetic field. The implantable cochlear stimulator 1110 may cause acurrent to flow through the implantable induction coil 1122 to generatethe telemetry magnetic field. The external induction coil 1120 may bepositioned at least partially within the telemetry magnetic fieldgenerated by the implantable induction coil 1122. The magnetic field maycause an electric current to be generated in the external induction coil1120. The current generated in the external induction coil 1120 may beused to transfer data and/or other signals to the sound processor 1106.

The communication link 1118 may include more than one external inductioncoil 1120 and/or more than one implantable induction coil 1122. Forexample, a first external induction coil and a first implantableinduction coil may be used to transfer data and/or power from the soundprocessor 1106 to the implantable cochlear stimulator 1110. A secondexternal induction coil and a second implantable induction coil may beused to transfer data from the implantable cochlear stimulator 1110 tothe sound processor 1106.

FIG. 12 is a functional block diagram of an exemplary sound processor1106 and implantable cochlear stimulator 1110. The functions shown inFIG. 12 are merely representative of the many different functions thatmay be performed by the sound processor 1106 and/or the implantablecochlear stimulator 1110.

As shown in FIG. 12, the microphone 1108 senses an audio signal, such asspeech or music, and converts the audio signal into one or moreelectrical signals. These signals are then amplified in audio front-end(AFE) circuitry 1202. The amplified audio signal is then converted to adigital signal by an analog-to-digital (ND) converter 1204. Theresulting digital signal is then subjected to automatic gain controlusing a suitable automatic gain control (AGC) function 1206.

After appropriate automatic gain control, the digital signal is thenprocessed in one of a number of digital signal processing or analysischannels 1208. For example, the sound processor 1106 may include, but isnot limited to, sixteen analysis channels 1208. Each analysis channel1208 may respond to a different frequency band of the sensed audiosignal due to a series of band pass filters 1210.

As shown in FIG. 12, each of them analysis channels 1208 may alsoinclude an energy detection stage (D1-Dm) 1212. Each energy detectionstage 1212 may include any combination of circuitry configured to detectthe amount of energy contained within each of the m analysis channels1208. For example, each energy detection stage 1212 may include arectification circuit followed by an integrator circuit.

After energy detection, the signals within each of the m analysischannels 1208 are forwarded to a mapping stage 1214. The mapping stage1214 is configured to map the signals in each of the m analysis channels1208 to one or more of M stimulation channels 1218. In other words, theinformation contained in the m analysis channels 1208 is used to definethe electrical stimulation pulses that are applied to the patient by theimplantable cochlear stimulator 1110 via the M stimulation channels1218. As mentioned previously, pairs or groups of individual electrodes1112 may make up the M stimulation channels 1218.

In some examples, the mapped signals are serialized by a multiplexer1216 and transmitted to the implantable cochlear stimulator 1110. Theimplantable cochlear stimulator 1110 may then apply electricalstimulation via one or more of the M stimulation channels 1218 to one ormore stimulation sites within the duct of the patient's cochlea. As usedherein, the term “stimulation site” will be used to refer to a targetarea or location to which the electrical stimulation is applied. Forexample, a stimulation site may refer to any location within a region ofauditory nerve tissue (e.g., auditory nerve tissue 1306 shown in FIG.13).

FIG. 13 illustrates a schematic structure of the human cochlea 1300. Asshown in FIG. 13, the cochlea 1300 is in the shape of a spiral beginningat a base 1302 and ending at an apex 1304. Within the cochlea 1300resides auditory nerve tissue 1306, which is denoted by Xs in FIG. 13.The auditory nerve tissue 1306 is organized within the cochlea 1300 in atonotopic manner. Low frequencies are encoded at the apex 1304 of thecochlea 1300 while high frequencies are encoded at the base 1302. Hence,each location along the length of the cochlea 1300 corresponds to adifferent perceived frequency. A cochlear prosthesis may therefore beimplanted within a patient with sensorineural hearing loss andconfigured to apply electrical stimulation to different locations withinthe cochlea 1300 to provide the sensation of hearing. For example,electrode lead 1114 may be disposed within the cochlea 1300 such thatelectrodes 1112 contact auditory nerve tissue 1306 within the cochlea1300. Electrical stimulation may be applied by the electrodes 1112 tothe auditory nerve tissue 1306.

FIG. 14 illustrates an exemplary configuration of cochlear implantsystem 1100 that may be used to apply electrical stimulation one or morestimulation sites within the cochlea 1300. As shown in FIG. 14, theexternal portion of the cochlear implant system 1100 may include anexternal headpiece 1400 configured to be worn on an exterior of a head1402 of the patient. The external headpiece 1400 may include variouscomponents of the sound processor portion 1102, including the externalinduction coil 1122 (not shown), as will be described in greater detailbelow. The external headpiece 1400 may additionally include electroniccircuitry, such as circuitry comprising at least a portion of the soundprocessor 1106. The external headpiece 1400 may be electricallyconnected, either directly or indirectly, to a microphone 1108 (notshown) positioned in or near the patient's ear via a communication line1404. The headpiece 1400 may additionally include a retention magnet toposition and maintain the headpiece 1400 in a proper orientation on thehead 1402, as will be described in greater detail below.

As shown in FIG. 14, an implantable cochlear stimulator 1110 may bedisposed underneath the skin 1406 of the patient. A lead 1114 with aplurality of electrodes 1112 disposed on a distal portion thereof may becoupled to the implantable cochlear stimulator 1110 and positioned suchthat the electrodes 1112 are disposed within the cochlea 1300.

In some examples, the implantable cochlear stimulator 1110 may include areceiver 1408 configured to facilitate communication with the externalheadpiece 1400. The receiver 1408 may include the implantable inductioncoil 1122 (not shown) described above.

The external induction coil 1120 in the external headpiece 1400 and theimplantable induction coil 1122 in the receiver 1408 may formcommunication link 1118. As described above, data and/or power may betransmitted between the sound processor portion 1102 and the cochlearstimulation portion 1104 via the communication link 1118. For example,the external induction coil 1120 in the external headpiece 1400 maytransmit a telemetry signal across the skin 1406 to the implantableinduction coil 1122 in the receiver 1408. Additionally or alternatively,the implantable induction coil 1122 in the receiver 1408 may transmit atelemetry signal across the skin 1406 to the external induction coil1120 in the external headpiece 1400.

FIGS. 15A-15C illustrate an exemplary external headpiece 1400 that maybe used in accordance with present systems and methods. The componentsshown in FIGS. 15A-15C are merely illustrative of the many differentcomponents that may be included within headpiece 1400. Additional oralternative components may be included within headpiece 1400 as mayserve a particular application.

FIG. 15A is an exploded perspective view of the exemplary externalheadpiece 1400 showing various components of the external headpiece1400. FIG. 15A is a perspective view of the exemplary external headpiece1400 shown without a headpiece cover. FIG. 15C is cross-sectional sideview of the exemplary external headpiece 1400 shown without a headpiececover. As shown in FIGS. 15A-15C, the external headpiece 1400 mayinclude a headpiece cover 1500 in which a headpiece cavity 1502 isdefined. The external headpiece 1400 may additionally include aheadpiece base 1504 that may be attached to the headpiece cover 1500.Components in the external headpiece 1400 may be housed in the headpiececavity 1502 such that they are substantially surrounded by headpiececover 1500 and the headpiece base 1504.

The external headpiece 1400 may include a circuit board 1506 (e.g., aprinted circuit board) having electronic circuitry 1508 disposedthereon. The electronic circuitry 1508 may be disposed on any suitableportions of the circuit board 1506. A bottom surface 1510 of the circuitboard 1506 may face generally towards the headpiece base 1504. Theelectronic circuitry 1508 may include the sound processor 1106 or atleast a portion of the sound processor 1106. The electronic circuitry1508 may be configured to direct the implantable cochlear stimulator1110 to generate and apply electrical stimulation to one or morestimulation sites within the cochlea 1300 of a patient by transmittingcontrol parameters (including, but not limited to, stimulationparameters) to the implantable cochlear stimulator 1110 viacommunications link 1118. The electronic circuitry 1508 may additionallyor alternatively be configured to transmit power to the implantablecochlear stimulator 1110 and may be configured to receive data from thecochlear stimulator 1110.

The external headpiece 1400 may further include an induction coil 1512disposed below the bottom surface 1510 of the circuit board 1506. Theinduction coil 1512 may include a metallic wire or tube wound in acoiled configuration. In some examples, the induction coil 1512 mayinclude a coiled wire arranged in a generally disc-shaped and/orannular-shaped holder. It will be recognized that the induction coil1512 may have any suitable size and shape as may serve a particularapplication.

The induction coil 1512 may have a top surface 1514 and an interiorradial surface 1516, as illustrated in FIG. 15A. The induction coil 1512may be seated in the headpiece base 1504. Accordingly, the inductioncoil 1512 may be in close proximity to the head 1402 of the patient whenthe headpiece base 1504 is adjacent to the head 1402.

In some examples, the external headpiece 1400 may additionally include atelemetry flux guide 1518 positioned or disposed between the circuitboard 1506 and the induction coil 1512. The telemetry flux guide 1518may have a generally annular shape with an inner radial surface 1520defining an aperture extending through a central portion of thetelemetry flux guide 1518. The telemetry flux guide may be adjacent tothe bottom surface 1510 of the circuit board 1506 and the top surface1514 of the induction coil 1512.

The telemetry flux guide 1518 may include any material suitable fordirecting magnetic flux away from the circuit board 1506. For example,the telemetry flux guide 1518 may include a material having a relativelyhigh resistivity that provides a low reluctance path for magnetic fluxof the telemetry magnetic field. Additionally, the telemetry flux guide1518 may include a powdered material, such as a powdered metallicmaterial having a relatively small particle size, in order to preventthe generation of eddy current in the telemetry flux guide 1518. Forexample, eddy currents might be generated in a solid conductive material(as opposed to a powdered conductive material) in the presence of thetelemetry magnetic field since the telemetry magnetic field is achanging magnetic field generated by an alternating current passingthrough the induction coil 1512.

The powdered material in telemetry flux guide 1518 may be held togetherusing any suitable material, such as a polymer material. In someexamples, the powdered metallic material may include iron and/or otherferrite materials. Additionally, the telemetry flux guide 1518 may besuitable for frequencies of telemetry signals generated and/or receivedby the induction coil 1512, such as, for example, an approximately 49MHz telemetry signal and/or an approximately 10.7 MHz telemetry signal.A telemetry flux guide 1518 including a material having a relativepermeability (i.e., the ratio of the permeability of the alloy to thepermeability of free-space) of approximately 9 may be suitable for afrequency range that includes 49 MHz and 10.7 MHz telemetry signals.However, it will be recognized that the telemetry flux guide 1518 mayhave any other suitable relative permeability value as may serve aparticular application. Additionally or alternatively, telemetry fluxguide 1518 may have a relatively high resistivity and a relatively smallparticle size in order to facilitate redirection of magnetic flux whileminimizing the generation of eddy currents in the telemetry flux guide1518.

The telemetry flux guide 1518 may be positioned and configured to directmagnetic flux of the magnetic field generated by the induction coil 1512away from the circuit board 1506, as will be described in greater detailbelow. For example, a telemetry magnetic field may generated by theinduction coil 1512 to transmit a telemetry signal. Magnetic flux of thetelemetry magnetic field may be directed away from the circuit board1506 by the telemetry flux guide 1518, thereby protecting the electroniccircuitry 1508 on the circuit board 1506 from the telemetry magneticfield. By directing the magnetic flux in the telemetry magnetic fieldaway from the circuit board 1506, energy losses from the induction coil1512 to the electronic circuitry 1508 via the telemetry magnetic fieldmay be minimized, thereby extending the life of batteries used toprovide power to one or more components of the cochlear implant system1100.

In some examples, the external headpiece 1400 may additionally oralternatively include a retention magnet 1522 disposed between thecircuit board 1506 and the headpiece base 1504. The retention magnet1522 may have a top surface 1524 generally facing the bottom surface1510 of the circuit board 1506. The retention magnet 1522 mayadditionally have an outer radial surface 1526. In some embodiments, theretention magnet 1522 may be positioned in the external headpiece 1400such that the retention magnet 1522 is at least partially surrounded bythe induction coil 1512 and/or the telemetry flux guide 1518.Accordingly, the outer radial surface 1526 of the retention magnet 1522may generally face the inner radial surface 1516 of the induction coil1512 and/or the inner radial surface 1520 of the telemetry flux guide1518. For example, the retention magnet 1522 may be positioned in anaperture defined by the inner radial surface 1520 extending through thetelemetry flux guide 1518.

The retention magnet 1522 may be configured to produce a retentionmagnetic field for securing one or more components of a cochlear implantsystem 1100 to a head 1402 of a patient. For example, the retentionmagnet 1522 may be disposed adjacent to the headpiece base 1504 suchthat the retention magnet 1522 is in close proximity to the head 1402 ofthe patient when the headpiece base 1504 is adjacent to the head 1402. Aportion of the cochlear stimulation portion 1104 of the cochlear implantsystem 1100, such as the receiver 1408 shown in FIG. 14, may similarlyinclude a magnet configured to magnetically couple with the retentionmagnet 1522. Accordingly, when the headpiece base 1504 is positionedadjacent to the head 1402 of the patient near the receiver 1408, theretention magnet 1522 may be magnetically coupled to the magnet of thecochlear stimulation portion 1104, thereby securing and/or orienting theexternal headpiece 1400 on the head 1402.

The external headpiece 1400 may additionally or alternatively include aretention flux guide 1528 positioned between the circuit board 1506 andthe retention magnet 1522. The retention flux guide 1528 may at leastpartially surround the retention magnet 1522. As illustrated in FIGS.15A and 15C, a top wall 1530 of the retention flux guide 1528 may bedisposed in between and adjacent to the bottom surface 1510 of thecircuit board 1506 and the top surface 1524 of the retention magnet1522. Additionally, a side wall 1532 of the retention flux guide 1528may at least partially surround the outer radial surface 1526 of theretention magnet 1522. The side wall 1532 of the retention flux guide1528 may be adjacent to the outer radial surface 1526 of the retentionmagnet 1522, the inner radial surface 1516 of the induction coil 1512,and/or the inner radial surface 1520 of the telemetry flux guide 1518.

The retention flux guide 1528 may include any material suitable forredirecting magnetic flux associated with a magnetic field produced bythe retention magnet 1522. For example, the retention flux guide 1528may include a material having a relatively high permeability. In someexamples, the retention flux guide 1528 may include a metallic material,such as a mu-metal alloy comprising nickel and iron. A relatively highpermeability mu-metal alloy may have a relative permeability betweenapproximately 60,000 and 300,000. For example, a mu-metal alloy may havea relative permeability of approximately 100,000. A high-permeabilitymu-metal alloy may include any suitable ratio of nickel and iron, suchas, for example, a ratio of approximately 80% nickel and 20% iron. Itwill be recognized that the retention flux guide 1528 may alternativelyinclude any suitable material having any suitable relative permeability.

The retention flux guide 1528 may be configured to direct magnetic fluxof a retention magnetic field surrounding the retention magnet 1522 awayfrom the circuit board 1506 and/or away from the telemetry flux guide1518. Accordingly, magnetic flux from the retention magnet 1522 may bedirected away from the circuit board 1506, thereby protecting theelectronic circuitry 1508 on the circuit board 1506 from the retentionmagnetic field.

As mentioned, the retention flux guide 1528 may also direct magneticflux of the retention magnetic field away from the telemetry flux guide1518, thereby preventing saturation of powdered metallic material in thetelemetry flux guide 1518 with magnetic flux from the retention magnet.Magnetic flux from the retention magnet 1522 may significantly reducethe relative permeability of the powdered metallic material in thetelemetry flux guide 1518, reducing the effectiveness of the telemetryflux guide 1518 in directing magnetic flux from the induction coil 1512away from the circuit board 1506. Accordingly, the retention flux guide1528 may direct magnetic flux of the retention magnetic field away fromthe telemetry flux guide 1518, thereby preventing magnetic flux fromsaturating the telemetry flux guide 1518.

By directing magnetic flux away from the electronic circuitry 1508 inthe circuit board 1506, the telemetry flux guide 1518 and/or theretention flux guide 1528 may enable the induction coil 1512 and/or theretention magnet 1522 to be located within the external headpiece 1400in relatively close proximity to the circuit board 1506. Accordingly,the sound processor portion 1102 of the cochlear implant system 1100 maybe made more compact by consolidating electronic and magnetic fieldemitting components within the headpiece as illustrated in FIGS.15A-15C. This may increase the ease of use and comfort for a patientusing the cochlear implant system 1100 in comparison to conventionalcochlear implant systems in which electronic circuitry is separated fromthe headpiece. For example, a consolidated unit, such as thatillustrated in FIGS. 15A-15C, may eliminate the need for a separatebehind-the-ear unit. Hence, the unit illustrated in FIGS. 15A-15C may bereferred to as a “one piece system headpiece”.

By directing magnetic flux away from the electronic circuitry 1508 inthe circuit board 1506, the telemetry flux guide 1518 and/or theretention flux guide 1528 may enable the induction coil 1512 and/or theretention magnet 1522 to be located within the external headpiece 1400in relatively close proximity to the circuit board 1506. Accordingly,the sound processor portion 1102 of the cochlear implant system 1100 maybe made more compact by consolidating electronic and magnetic fieldemitting components within the headpiece as illustrated in FIGS.15A-15C. This may increase the ease of use and comfort for a patientusing the cochlear implant system 1100 in comparison to conventionalcochlear implant systems in which electronic circuitry is separated fromthe headpiece. For example, a consolidated assembly, such as thatillustrated in FIGS. 15A-15C, may eliminate the need for a separatebehind-the-ear assembly. Hence, the assembly illustrated in FIGS.15A-15C may be referred to as a “one piece system headpiece”.

In some embodiments, the cochlear stimulation portion 1104 of a cochlearimplant system 1100 may additionally or alternatively include aretention flux guide and/or a telemetry flux guide for directingmagnetic flux away from electronic components in the cochlearstimulation portion 1104. For example, a receiver 1408 in the cochlearstimulation portion 1104 may include an induction coil and/or aretention magnet, similar to the external headpiece 1400 as describedabove. A retention flux guide and/or a telemetry flux guide may beincluded in the receiver 1408 to redirect magnetic flux away fromelectronic circuitry that may be located in close proximity to theinduction coil and/or the retention magnet.

Additionally, as illustrated in FIGS. 15B and 15C, the externalheadpiece 1400 may include one or more batteries 1534 to power the soundprocessor portion 1102 and/or the cochlear stimulation portion 1102 ofthe cochlear implant system 1100. Batteries 1534 may be disposed withinthe headpiece cover cavity 1502 of the headpiece cover 1500 and may belocated adjacent circuit board 1506. In some embodiments, batteries 1534may be located outside of the external headpiece 1400.

FIG. 16 illustrates magnetic flux surrounding an induction coil 1512 anda retention magnet 1522 in an exemplary external headpiece 1400 inaccordance with the present systems and methods. As illustrated in FIG.16, magnetic flux 1600 may surround the induction coil 1512. Themagnetic flux 1600 is represented as a flux path surrounding theinduction coil 1512. Additionally, magnetic flux 1602 may pass throughand surround retention magnet 1522. The magnetic flux 1602 isrepresented as flux paths surrounding and passing through the retentionmagnet 1522. It will be recognized that additional flux paths other thanthose illustrated in FIG. 16 may be associated with the telemetrymagnetic field surrounding the induction coil 1512 and the retentionmagnetic field surrounding the retention magnet 1522.

The telemetry flux guide 1518 may provide a low reluctance path for themagnetic flux 1600 surrounding the induction coil 1512. As illustratedin FIG. 16, the path of the magnetic flux 1600 may be directed throughthe telemetry flux guide 1518 such that a path of the magnetic flux 1600between the induction coil 1512 and the circuit board 1506 may beshortened. The magnetic flux 1600 of the telemetry magnetic flux fieldsurrounding the induction coil 1512 may therefore be redirected by thetelemetry flux guide 1518 such that the magnetic flux 1600 issubstantially prevented from reaching the circuit board 1506, therebyreducing or eliminating magnetic flux passing through the electroniccircuitry 1508.

The retention flux guide 1528 may provide a high permeability path forthe magnetic flux 1602 surrounding and passing through the retentionmagnet 1522. As illustrated in FIG. 16, the path of the magnetic flux1602 may be directed through the retention flux guide 1528 such that apath of the magnetic flux 1602 passes generally through and/or along thetop wall 1530 and/or the side wall 1532 of the retention flux guide1528. Accordingly, a path of the magnetic flux 1602 between theinduction coil 1512 and the circuit board 1506 may be shortened.Similarly, a path of the magnetic flux 1602 between the retention magnet1522 and the telemetry flux guide 1518 may be shortened. The magneticflux 1602 of the retention magnetic flux field surrounding and passingthrough the retention magnet 1522 may therefore be redirected by theretention flux guide 1528 such that the magnetic flux 1602 issubstantially prevented from reaching the circuit board 1506 and/or thetelemetry flux guide 1518, thereby reducing or eliminating magnetic fluxfrom the retention magnet passing through the electronic circuitry 1508and/or the telemetry flux guide 1518.

The preceding description has been presented only to illustrate anddescribe embodiments and examples of the principles described. Thisdescription is not intended to be exhaustive or to limit theseprinciples to any precise form disclosed. Many modifications andvariations are possible in light of the above teaching.

What is claimed is:
 1. A headpiece for use with a cochlear implant,comprising: a headpiece housing that is not a behind-the-ear soundprocessor housing; a microphone within the headpiece housing thatoutputs an audio signal; signal processing electronics within theheadpiece housing that process the audio signal into a processed audiosignal; a retention magnet within the headpiece housing that generates aretention magnetic field; an induction coil within the headpiece housingthat transmits the processed audio signal received from the signalprocessing electronics to the cochlear implant by generating a telemetrymagnetic field; and a retention flux guide, within the headpiece housingbetween the retention magnet and the signal processing electronics, thatdirects magnetic flux associated with the retention magnetic field awayfrom the signal processing electronics.
 2. A headpiece as claimed inclaim 1, wherein the retention flux guide is formed from a materialhaving a relatively high permeability.
 3. A headpiece as claimed inclaim 1, further comprising: a power source within the headpiece housingthat supplies electrical power for the microphone, the signal processingelectronics and the induction coil.
 4. A headpiece as claimed in claim3, wherein the power source comprises a battery.
 5. A headpiece asclaimed in claim 3, wherein the signal processing electronics are on acircuit board; and the circuit board is positioned between the powersource and the induction coil.
 6. A headpiece as claimed in claim 1,further comprising: an assistive listening device cap.
 7. A headpiece asclaimed in claim 1, further comprising: a receiver within the headpiecehousing.
 8. A headpiece as claimed in claim 1, further comprising: atelemetry flux guide, within the headpiece housing between the inductioncoil and the signal processing electronics, that directs magnetic fluxassociated with the telemetry magnetic field away from the signalprocessing electronics.
 9. A headpiece as claimed in claim 8, whereinthe signal processing electronics are on a circuit board; and thetelemetry flux guide is positioned between the induction coil and thecircuit board.
 10. A headpiece as claimed in claim 8, wherein thetelemetry flux guide directs the magnetic flux associated with thetelemetry magnetic field away from the signal processing electronics.11. A headpiece as claimed in claim 1, wherein the headpiece housingincludes a base and a cover.
 12. A headpiece as claimed in claim 11,wherein the induction coil is seated on the base; and a power source ispositioned within a cavity defined by the cover.
 13. A headpiece asclaimed in claim 12, wherein the power source defines a plurality ofbatteries.
 14. A headpiece as claimed in claim 11, wherein the base andthe cover define a cavity in which the microphone, the signal processingelectronics, the induction coil and the retention flux guide arelocated.
 15. A headpiece as claimed in claim 1, wherein the retentionflux guide is formed from a mu-metal alloy.
 16. A headpiece as claimedin claim 1, wherein the retention flux guide is formed from a mu-metalalloy having a relative permeability between approximately 60,000 and300,000.
 17. A headpiece as claimed in claim 1, wherein the retentionflux guide at least partially surrounds the retention magnet.
 18. Aheadpiece as claimed in claim 1, wherein the retention magnet defines anouter radial surface; and the retention flux guide at least partiallysurrounds the outer radial surface of the retention magnet.
 19. Aheadpiece for use with a cochlear implant, comprising: a headpiecehousing that is not a behind-the-ear sound processor housing; amicrophone within the headpiece housing that outputs an audio signal;signal processing electronics within the headpiece housing that processthe audio signal into a processed audio signal; an induction coil withinthe headpiece housing that transmits the processed audio signal receivedfrom the signal processing electronics to the cochlear implant bygenerating a telemetry magnetic field; a telemetry flux guide, withinthe headpiece housing between the induction coil and the signalprocessing electronics, that defines an annular shape and directsmagnetic flux associated with the telemetry magnetic field away from thesignal processing electronics; and a retention magnet within theheadpiece housing that generates a retention magnetic field and is atleast partially surrounded by the induction coil and/or the telemetryflux guide.
 20. A headpiece for use with a cochlear implant, comprisinga headpiece housing that is not a behind-the-ear sound processorhousing; a microphone within the headpiece housing that outputs an audiosignal; signal processing electronics within the headpiece housing thatprocess the audio signal into a processed audio signal; a retentionmagnet within the headpiece housing that generates a retention magneticfield; means for transmitting the processed audio signal received fromthe signal processing electronics to the cochlear implant by generatinga telemetry magnetic field; and means, within the headpiece housingbetween the retention magnet and the signal processing electronics, fordirecting magnetic flux associated with the retention magnetic fieldaway from the signal processing electronics; wherein all of themicrophone, the signal processing electronics, the means fortransmitting, and the means for directing magnetic flux associated withthe retention magnetic field are disposed within the housing.
 21. Aheadpiece as claimed in claim 20, wherein the signal processingelectronics are on a circuit board; and the means for directing magneticflux associated with the telemetry magnetic field is positioned betweenthe means for transmitting and the circuit board.
 22. A headpiece asclaimed in claim 20, further comprising: means, between the means fortransmitting and the signal processing electronics, for directingmagnetic flux associated with the telemetry magnetic field away from thesignal processing electronics.
 23. A headpiece as claimed in claim 20,further comprising: a power source within the headpiece housing thatsupplies electrical power for the microphone, the signal processingelectronics and the means for transmitting.
 24. A headpiece as claimedin claim 23, wherein the power source comprises a battery.
 25. Aheadpiece as claimed in claim 23, wherein the signal processingelectronics are on a circuit board; and the circuit board is positionedbetween the power source and the circuit board.
 26. A headpiece asclaimed in claim 20, wherein the headpiece housing includes a base and acover.
 27. A headpiece as claimed in claim 26, wherein the means fortransmitting is seated on the base; and a power source is positionedwithin a cavity defined by the cover.
 28. A headpiece as claimed inclaim 27, wherein the power source defines a plurality of batteries. 29.A headpiece as claimed in claim 20, wherein the base and the coverdefine a cavity in which the microphone, the signal processingelectronics, the means for transmitting and the means for directingmagnetic flux associated with the retention magnetic field are located.